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What happens when plants get more gas?

What happens when plants get more gas?

We know that most plants use carbon dioxide to make their own food. So what might plants look like in 100 years if carbon dioxide levels continue to increase - will they become enormous and overtake our backyards? View the possible effects of changes in atmospheric carbon dioxide on plants and, in turn, humans and other animals.

Things to think about

1

Before viewing

Plants are often at the beginning of a food chain. How do they produce their own food?

In what ways are humans and other animals dependent on plants?

2

As you view

One way plants may respond to increased levels of carbon dioxide is to grow faster. Is this what happens?

Watch the animation showing how plants capture carbon dioxide and identify the role played by protein.

What is the connection between the amount of protein a plant has, and the nutrition value and protection measures of the plant?

3

After viewing

Draw a flow chart or a labelled diagram to show how increased carbon dioxide levels may impact plants, taking into account photosynthesis, protein levels and plant responses.

Use your flow chart to show how koalas and grasshoppers might be affected.

How might living and non-living things, such as pests and weather, change as a result of altered carbon dioxide levels?

4

Next steps

Find out about some of the causes of increased carbon dioxide levels in the atmosphere.

Research the concentration of atmospheric gases including carbon dioxide over geological time. In what geological period/s were carbon dioxide levels higher than today?

Transcript

00:00:01:10DR GRAHAM PHILLIPS:The next big food issue could be how rising levels of carbon dioxide affect our fruit and vegies. Now, we know that plants love CO2, so rising levels of it will affect their metabolisms. And it seems almost certain that for many foods the levels of nutrition will go down and, for some, toxin levels will go up - both serious issues when trying to feed a world with increasing population.00:00:24:08DR ROS GLEADOW:We're tracking worst-case scenario with carbon dioxide at the moment. And we need to predict what sort of things are going to happen in the future.00:00:37:00DR GRAHAM PHILLIPS:Carbon dioxide is crucial for plant growth. Plants breathe in CO2 and convert the gas into usable energy.00:00:46:08DR ROS GLEADOW:Plants use carbon dioxide. It's a carbon catcher and storage system, so you think if there's more carbon dioxide they would just capture and store more. But, in fact, that doesn't happen. Plants do grow faster at elevated carbon dioxide, usually, but not as fast as you'd expect.00:01:05:06DR GRAHAM PHILLIPS:Ros Gleadow has been studying the effects of raised C02 on plant growth.00:01:10:12DR ROS GLEADOW:Leaves of plants grown at elevated carbon dioxide have a lot less protein in them. Wheat, barley, rice, all of those in probably only 50 to 60 years' time will have 15% to 20% less protein in them than they do now.00:01:25:23DR GRAHAM PHILLIPS:So why would a plant have less protein in a raised-carbon dioxide environment? In the process of photosynthesis, plants carbon dioxide into sugars, using a protein called Rubisco to capture the CO2 from the atmosphere. If carbon dioxide levels increase, plants will need to produce less Rubisco to capture the same amount of carbon dioxide. Less of this protein means a less nutritious meal. And the plant's extra resources can then be diverted into protecting the plant. Plants protect themselves using spines and thorns or make themselves less appetising by producing toxic chemicals. Eucalypts produce phenols.00:02:13:21DR ROS GLEADOW:In about 50 years' time or even 100 years' time eucalyptus leaves will have trouble supporting arboreal herbivores, like koalas, because the phenolic concentration will be too high and the protein level too low.00:02:27:17DR GRAHAM PHILLIPS:Phenols are one way that plants protect themselves from animal attack, but there is another way - cyanide.00:02:35:19PROFESSOR HOWARD BRADBURY:If an insect comes and eats the leaf, then it immediately gets a nasty taste of bitter hydrogen cyanide, so it goes somewhere else. So this is a really great mechanism for protecting the plant. And there's about 2,000 plants use this mechanism, including apples, apricots, peaches.

For teachers

Year 9 Science Strand: Science UnderstandingSubstrand: Biological sciencesContent code: ACSSU176Description: Ecosystems consist of communities of interdependent organisms and abiotic components of the environment; matter and energy flow through these systems

Year 9 Science Strand: Science as a Human EndeavourSubstrand: Use and influence of scienceContent code: ACSHE228Description: The values and needs of contemporary society can influence the focus of scientific research

Year 10 Science Strand: Science as a Human EndeavourSubstrand: Use and influence of scienceContent code: ACSHE194Description: People can use scientific knowledge to evaluate whether they should accept claims, explanations or predictions

What to view next:

What happens when plants get more gas?

Overview

We know that most plants use carbon dioxide to make their own food. So what might plants look like in 100 years if carbon dioxide levels continue to increase - will they become enormous and overtake our backyards? View the possible effects of changes in atmospheric carbon dioxide on plants and, in turn, humans and other animals.

Things to think about

Before viewing

Plants are often at the beginning of a food chain. How do they produce their own food?

In what ways are humans and other animals dependent on plants?

2

As you view

One way plants may respond to increased levels of carbon dioxide is to grow faster. Is this what happens?

Watch the animation showing how plants capture carbon dioxide and identify the role played by protein.

What is the connection between the amount of protein a plant has, and the nutrition value and protection measures of the plant?

3

After viewing

Draw a flow chart or a labelled diagram to show how increased carbon dioxide levels may impact plants, taking into account photosynthesis, protein levels and plant responses.

Use your flow chart to show how koalas and grasshoppers might be affected.

How might living and non-living things, such as pests and weather, change as a result of altered carbon dioxide levels?

4

Next steps

Find out about some of the causes of increased carbon dioxide levels in the atmosphere.

Research the concentration of atmospheric gases including carbon dioxide over geological time. In what geological period/s were carbon dioxide levels higher than today?

Transcript

00:00:01:10DR GRAHAM PHILLIPS:The next big food issue could be how rising levels of carbon dioxide affect our fruit and vegies. Now, we know that plants love CO2, so rising levels of it will affect their metabolisms. And it seems almost certain that for many foods the levels of nutrition will go down and, for some, toxin levels will go up - both serious issues when trying to feed a world with increasing population.00:00:24:08DR ROS GLEADOW:We're tracking worst-case scenario with carbon dioxide at the moment. And we need to predict what sort of things are going to happen in the future.00:00:37:00DR GRAHAM PHILLIPS:Carbon dioxide is crucial for plant growth. Plants breathe in CO2 and convert the gas into usable energy.00:00:46:08DR ROS GLEADOW:Plants use carbon dioxide. It's a carbon catcher and storage system, so you think if there's more carbon dioxide they would just capture and store more. But, in fact, that doesn't happen. Plants do grow faster at elevated carbon dioxide, usually, but not as fast as you'd expect.00:01:05:06DR GRAHAM PHILLIPS:Ros Gleadow has been studying the effects of raised C02 on plant growth.00:01:10:12DR ROS GLEADOW:Leaves of plants grown at elevated carbon dioxide have a lot less protein in them. Wheat, barley, rice, all of those in probably only 50 to 60 years' time will have 15% to 20% less protein in them than they do now.00:01:25:23DR GRAHAM PHILLIPS:So why would a plant have less protein in a raised-carbon dioxide environment? In the process of photosynthesis, plants carbon dioxide into sugars, using a protein called Rubisco to capture the CO2 from the atmosphere. If carbon dioxide levels increase, plants will need to produce less Rubisco to capture the same amount of carbon dioxide. Less of this protein means a less nutritious meal. And the plant's extra resources can then be diverted into protecting the plant. Plants protect themselves using spines and thorns or make themselves less appetising by producing toxic chemicals. Eucalypts produce phenols.00:02:13:21DR ROS GLEADOW:In about 50 years' time or even 100 years' time eucalyptus leaves will have trouble supporting arboreal herbivores, like koalas, because the phenolic concentration will be too high and the protein level too low.00:02:27:17DR GRAHAM PHILLIPS:Phenols are one way that plants protect themselves from animal attack, but there is another way - cyanide.00:02:35:19PROFESSOR HOWARD BRADBURY:If an insect comes and eats the leaf, then it immediately gets a nasty taste of bitter hydrogen cyanide, so it goes somewhere else. So this is a really great mechanism for protecting the plant. And there's about 2,000 plants use this mechanism, including apples, apricots, peaches.

For teachers

Science: Year 9Strand: Science UnderstandingSubstrand: Biological sciencesContent code: ACSSU176Content description:Ecosystems consist of communities of interdependent organisms and abiotic components of the environment; matter and energy flow through these systems

Science: Year 9Strand: Science as a Human EndeavourSubstrand: Use and influence of scienceContent code: ACSHE228Content description:The values and needs of contemporary society can influence the focus of scientific research

Science: Year 10Strand: Science as a Human EndeavourSubstrand: Use and influence of scienceContent code: ACSHE194Content description:People can use scientific knowledge to evaluate whether they should accept claims, explanations or predictions